The use of hydrocolloids in acidified milk products is well known. For example, Igoe (U.S. Pat. No. 4,046,925) teaches an acidified milk gel using a thickener system comprising carboxymethyl cellulose (CMC), locust bean gum (LBG), and xanthan gum. Schuppner (U.S. Pat. No. 3,726,690) teaches an acidified cream which is stabilized against serum separation with a mixture of LBG and xanthan gum. Haber (U.S. Pat. No. 4,081,567) teaches an acidified dry beverage mix which is reconstituted with cold milk. The mix contains starch, guar gum, and xanthan gum. In these products, the hydrocolloids have typically been used to thicken while also stabilizing them, i.e., preventing separation, whey-off, or co-aggulation of the milk protein under low pH conditions or the rigors of commercial processing.
A recently introduced concept in acidified milk products is the processed yogurt milk shake, i.e., a pasteurized yogurt product which upon shaking develops the froth characteristic of a milk shake. Such a product requires a foaming agent and stabilizer so that the product is stable, thickish in body, and retains its froth while being consumed.